1. Field of the Invention
The present invention relates in general to zero-idle-power, large area surfaces to redirect incident light, microwave or sound waves. The surfaces include multi-axis, large tilt angle, micromirror arrays that can be displaced or rotated by control signals from a central or remote controller to achieve desired beam or wavefront redirection in a pixelated manner.
2. Description of the Background Art
The costs for obtaining and using conventional fuels are making solar energy collection more attractive. Solar energy does present challenges, however, because it cannot be collected in sufficient density or quantity in a cost effective and efficient way. There are also problems with making, installing and using solar trackers, solar collectors and solar concentrators which will adapt to changing environmental lighting conditions.
In general, solar concentrators increase the flux of solar energy through a given area. This in turn can be used to maximize the power output of photovoltaic cells, which are significantly and nonlinearly improved in performance when irradiated by intense sunlight. Specially designed solar cells, which are optimized for use in intense sunlight, are capable of producing more output power than a large area of solar cells at a lower concentration due to the increased quantum efficiency of the cells in this intense light environment. Concentrators also provide a means to direct solar energy into a small cross-sectional area, thereby making solar energy distribution practical for a variety of uses. Unfortunately, solar concentrators have an intrinsically narrow field of view—diminishing with increasing concentration. This necessitates the use of some kind of tracking device to follow the sun's motion. Electronically controllable and adaptable solid-state solar trackers based on predominantly flat optical boundaries which refract the sunlight and have a reconfigurable orientation provide a means to direct light into a desired direction for the purpose of collection, concentration, distribution, and conversion of the sunlight into other end-use energy products, but have proven to be (a) difficult to manufacture (b) complicated to install and (c) expensive.
Many solar energy harvesting technologies are not practical because they cannot be integrated directly into buildings and other structures without a substantial mechanical infrastructure as is typical with conventional solar technologies.
In view of the foregoing, a need remains for a method and system for reducing the cost and complexity of collecting or directing solar energy so that solar power collecting structures (e.g., modular tiles) can be made and sold to consumers or end users.
There is also, more generally, an opportunity to fulfill needs for centrally or remotely controlled arrays of reflectors for redirecting incident energy or radiation including visible light, acoustic energy or RF/or microwave energy which is incident upon a defined surface or over a defined area.